The essays included in this volume are based on papers delivered at the International Symposium on Varieties of Marxism, held at the Van Leer Jerusalem Foundation on June 16-19,1974, and dedicated to the memory of George Lichtheim. When the idea of such a symposium was first raised, the organizers planned to have George Lichtheim as one of the main speakers at the event. In our last and brief meeting in London, I suggested this to him and Lichtheim gave his consent to attend the symposium, though at that time no date was yet fixed. His tragic death a few months later left a gap not only in the program of the symposium but in Marxist studies generally; it was felt that per haps one way of paying tribute to his contribution to the study of a subject so near to his mind would be to name the symposium in his memory and devote an introductory paper to an attempt at an intel lectual portrait of George Lichtheim as an historian of ideas. The volume as published includes all papers delivered at the sym posium, with the excep,tion of the papers of J. L. Talmon (Jerusalem) on 'Marxism and Nationalism' and Gajo Petrovic (Zagreb) on 'Yugo slav Marxism'. Appended is also a short obituary written by me on Lichtheim for the journal Political Science published by the American Political Science Association.